Sample Pretreatment And Chromatographic Analysis In Determination Of Toxic Residues In Food

Food safety concerns everyone's health and has attracted more attention around the world. With the expansion of industrial and agricultural production, more and more toxic substances are expelled to the surroundings, introduced into food chains, and accumulated in human bodies. Many of these compounds are carcinogenic, teratogenic and mutagenic to animals and human. Food safety has posed a series of life risks for people. Hence, the development of analysis methods for the determination of toxic substance residues in food is necessary to control food contamination and ensure food safety. There are two prominent problems in food analysis, one is the pretreatment means, and the other is the separation and determination method. Since the food matrices are complex and toxic residues are of trace level, furthermore, more rigid maximum residue limits (MRLs) have been established, more effective sample pretreatment and sensitive determination method should match the requirement of the rigid MRLs in food analysis. Sample pretreatment is the most difficult process, but important step in food analysis, which determines the sensitivity and feasibility of an analytical method.The main purpose of this thesis was to develop some simple, fast and cost-effective sample pretreatment methods and on-line analyte concentration methods to analysis of multiresidue pesticides, mycotoxins and other toxic additives residues in food samples with complex matrices. In addition, an on-line sample pretreatment system coupled with spectrophotometric determination was studied, including the interface technique, concentration mechanism and its application. The details in the contents and results of the thesis are as follows:1,A simple, fast and cost-effective method was developed for the determination of multiresidue pesticides in tea samples by matrix solid-phase dispersion (MSPD)-gas chromatography(GC). Response surface methodology (RSM) and desirability function approach were used to optimize the extraction conditions and evaluate the...